Fig 1.
Flow diagram of the study patients.
Table 1.
Patient and Tumor Characteristics.
Table 2.
Intraclass correlation coefficients (ICC) between 1-mm and 5-mm thickness CT data.
Fig 2.
An example of quantitative CT analysis in a recurred adenocarcinoma.
(A) CT scan and (B) screenshot of quantitative analysis show a 2.8-cm irregular nodule in the left lower lobe. The TNM stage was T1bN0M0 with stage IA. (C) The graph shows CT number (Hounsfield unit) distribution of the tumor. The perimeter of the tumor was 95.50 mm; area of tumor was 409.96 mm2; mean attenuation, 58.61 HU (Hounsfield unit); circularity, 0.57; aspect ratio 1.15; roundness, 0.87; skewness, -0.018; kurtosis, 0.39; and entropy, 7.01.
Fig 3.
An example of quantitative CT analysis in an adenocarcinoma without recurrence.
(A) CT scan and (B) screenshot of quantitative analysis show a 4.6-cm irregular nodule in the left upper lobe (T2aN1M0, stage IIA). (C) The graph shows CT number (Hounsfield unit) distribution of the tumor. The perimeter of the tumor was 159.02 mm; area of tumor was 1020.79 mm2; mean attenuation, 25.91 HU (Hounsfield unit); circularity, 0.51; aspect ratio 1.48; roundness, 0.67; skewness, 0.014; kurtosis, 0.21; and entropy, 7.06. The tumor attenuation is low, and is expected to no recurrence and the patient alive without recur for two years.
Fig 4.
Part-solid adenocarcinomas with or without recurrence.
(A) Mediastinal setting and (B) lung setting of CT images show a 3.2-cm part-solid adenocarcinoma in the right lower lobe (T2aN0M0, stage Ib). The lesion shows -315.27 HU (Hounsfield unit) and the area of lesion was 443.95 mm2. (C) The region of interest (ROI) for the tumor drawn in the ImageJ was noted. Lung metastasis was developed two years after the surgery. (D, E) A 2.1-cm part-solid nodule in the left lower lobe. The tumor area was 247.65 mm2 and the attenuation was -445.93 HU. (F) Air-bronchogram within the lesion was excluded for the measured ROI of the lesion. There was no recurrence in this patient for recent three years.
Table 3.
Univariate logistic regression analysis of 1-mm and 5-mm thickness CT data.
Fig 5.
Receiver operating curves to demonstrate the diagnostic performance of the independent predictive factors for tumor recurrence in both (A) 1-mm and (B) 5-mm CT data. The overall C-indices for 1-mm and 5-mm thickness CT images using two parameters (area and mean attenuation of tumors) are 0.80 (95% CI, 0.72–0.90) and 0.81 (0.72–0.90), respectively. AUC, area under the curve (C-index); CI, confidence interval.
Table 4.
Univariate and multivariable logistic regression of the quantitative CT parameters measured on 1-mm and 5-mm thickness CT data.